# Copyright (c) 2018 Presto Labs Pte. Ltd.
# Author: leon

import logging
import json
from typing import List, Union
import functools

from tornado import gen

import coin.flow.topic_map as topic_map
from coin.base.param_util import to_list
from coin.exchange.base.ws.subscriber import WebsocketJsonSubscriberBase


@functools.lru_cache(maxsize=64)
def parse_channel(channel):
  if channel.startswith('price_ladders_cash'):
    if channel.endswith('_buy') or channel.endswith('_sell'):
      return 'depth'
    else:
      return 'depth_single_channel'
  elif channel.startswith('executions_cash'):
    return 'trade'
  else:
    return 'Unknown'


class QuoinexSubscriber(WebsocketJsonSubscriberBase):
  def __init__(self,
               queue,
               group_id: str,
               worker_id: str,
               symbol: Union[List[str], str],
               close_callback=None,
               logger=None):
    super().__init__(close_callback, logger or logging.getLogger(__name__))
    self._symbol = to_list(symbol)

    self._register_url('wss://tap.liquid.com/app/LiquidTapClient?rate_limit=15kb')
    self._publisher = None
    self._init_publisher(queue, group_id, worker_id)

  def _init_publisher(self, queue, group_id: str, worker_id: str):
    topic_depth = topic_map.search_topic_id('quoinex_ws_depth_%s%s' % (group_id, worker_id))[0]
    topic_trade = topic_map.search_topic_id('quoinex_ws_trade_%s%s' % (group_id, worker_id))[0]

    self._publisher = {
        'depth': queue.get_writer(topic_id=topic_depth[1]),
        'trade': queue.get_writer(topic_id=topic_trade[1]),
    }

    self._enable_topic_event_publisher(queue,
                                       'quoinex_ws_topic_event', [topic_depth[0], topic_trade[0]])
    self._add_teardown_callback(self._teardown_publisher)

  @gen.coroutine
  def on_open(self):
    yield self._send_subscribe_request()
    super().on_open()

  @gen.coroutine
  def _send_subscribe_request(self):
    for symbol in self._symbol:
      self._logger.debug('Subscribing %s' % symbol)
      subscribe_depth_buy_str = json.dumps({
          'event': 'pusher:subscribe',
          'data': {
              'channel': 'price_ladders_cash_%s_buy' % symbol.lower()
          }
      })
      yield self._ws.write_message(subscribe_depth_buy_str)

      subscribe_depth_sell_str = json.dumps({
          'event': 'pusher:subscribe',
          'data': {
              'channel': 'price_ladders_cash_%s_sell' % symbol.lower(),
          }
      })
      yield self._ws.write_message(subscribe_depth_sell_str)

      subscribe_trade_str = json.dumps({
          'event': 'pusher:subscribe', 'data': {
              'channel': 'executions_cash_%s' % symbol.lower(),
          }
      })
      yield self._ws.write_message(subscribe_trade_str)

      yield gen.sleep(0.5)  # Sleep 0.5 second before next request

    self._publish_topic_event('START')
    self._logger.info('Subscribe done')

  def _teardown_publisher(self):
    if self._publisher:
      for _, publisher in self._publisher.items():
        publisher.close()
      self._publisher = None

  def on_message(self, timestamp: int, message: bytes):
    if self.stopped:
      return

    if 'channel' not in message:
      self._logger.warning('Unknown message: %s' % message)
      return
    channel = message['channel']

    if 'event' not in message:
      self._logger.warning('Unknown message: %s' % message)
      return
    event = message['event']

    if event not in ['updated', 'created']:
      # Subscribe response.
      return

    type = parse_channel(channel)
    try:
      self._publisher[type].write(timestamp, message)
    except (KeyError, ValueError):
      self._logger.error('Unknown channel: %s' % message)
